The basic design of a linear encoder is known, for example, from JP 2007-040873 A. The linear encoder is composed of a scale within a housing and of a scanning unit. The scanning unit includes a scanning head, which is disposed opposite the scale to allow scanning of the same and is displaceable relative thereto in the measuring direction, as well as a mount to which the scanning head is fastened inside of the housing. The scanning head itself is guided on the scale via guide elements. The mount is coupled via a driving component to a mounting base configured outside of the housing. Provided between the mount and the driving component is a compensating coupling that couples the scanning head to the driving component in the measuring direction rigidly and, in directions transversely thereto, flexibly.
This compensating coupling can cause errors during position measurement due to play, in particular in response to a change in direction.
For that reason, linear encoders have been developed that make do without such a coupling, where the scanning head is not guided on the scale. A linear encoder of this type is described in JP 2014-182054 A. Since no compensating coupling is provided between the mount and the scanning head, the position measuring cannot be negatively affected by any reversal error of a coupling.
JP 2006-147989 A describes a light exposure device that employs a vibration damper that is composed of an elastic element and a damping mass.
German Patent Application DE 10 2008 060 839 A1 describes a rotary encoder where a vibration damper is mounted externally on the fixed housing. The vibration damper is constituted of an elastic element upon which a damping mass is mounted.